1. Field of the Invention
The present invention relates to a battery charging apparatus for charging a secondary battery such as an Ni--Cd battery, and more particularly it relates to a battery charging apparatus being provided with a unit for exclusive use in charging and a unit for use in charging and discharging.
2. Description of Related Art
Recently, a cordless type of apparatus such as an 8 mm video camera has greatly been in common use, and accordingly, a secondary battery being used for its power source has also been brought into a variety of uses. When the secondary battery is generally used, plural pieces of a cell or a battery pack including more than two batteries are prepared, and after each piece of those has been exchanged to be used, those cells or battery packs are adapted to be charged to be reused. Among those plural cells or battery packs, however, depending on the time when they are purchased, there are some pieces whose battery capacity can not be recovered after they have been usually charged.
In order to avoid such inconvenience, there is disclosed an apparatus being provided with charging means and means for measuring and displaying the discharging life of a charged battery in Japanese Patent Application Laid-Open No. 62-141934.
The above prior art apparatus, after all of those cells or battery packs have been charged, discharges them in order to measure the discharging lives of those charged cells or battery packs. Among those cells or battery packs being owned by a user, there exist some which are purchased recently and are capable of fully being recovered by usual charging alone. For such cells or batteries, there is no need to repeat discharging and recharging after the usual charging.
For the above prior art apparatus, it is important that the battery pack can easily and surely be loaded or unloaded.
And it is also important to simplify the construction of the apparatus and to prevent the apparatus from being affected by a radio wave of noise from/to the outside.